Farms explore cover-cropping, rotational grazing

Tuesday

Feb 26, 2013 at 6:00 AM

Popular no-till practices like cover cropping and rotational livestock grazing have increasingly caught the attention of produce growers, but drought and water restrictions are holding back wider adoption.

By Candace KrebsContributing Writer

BRIGHTON, Colo. — Popular no-till practices like cover cropping and rotational livestock grazing have increasingly caught the attention of produce growers, but drought and water restrictions are holding back wider adoption.

Speaking at Colorado State University’s Colorado Agriculture Big and Small Conference, Helen Atthowe, a permaculture specialist who has consulted with Grant Family Farms of Wellington as well as farmers in Oregon and California — all while running a 200-acre research farm of her own in Western Montana — said that increasing plant diversity with legumes and other cover crops has proven to reduce pests, weeds and disease while improving soil fertility. On high value land in regions like the Salinas Valley, farmers are gaining similar advantages by moving to less disruptive cultivation practices.

“We need more research into which cover crops, living mulches and green manures are best with which crops and when,” she said.

One discovery she noted was the close correlation between early season nitrogen applications and increased weed pressure. “Anywhere we used compost manure and tillage, that brought out more annual weeds,” she said. On her farm, she prefers to leave islands of living mulch between the planted beds and mow them monthly.

Raising livestock and produce together was another ecological approach discussed during the conference. Eric Skokan, a nationally known chef considered a leader in the farm-to-table movement, described how he introduced livestock to his 130-acre Black Cat Farm that supplies most of the food he serves at two gourmet restaurants in neighboring Boulder.

The project started when he decided to raise his own ducks. The first time he cleaned out the coop, he vowed to eliminate that job by running them on his fields instead, where they would manure the soil while eating insects. “That was the seed for the whole thing,” he said.

Since then, he’s added heritage breeds of sheep, hogs, chickens and turkeys that are rotated with movable fencing through different parts of the farm in a complex two-year grazing plan. He estimated that about 20 percent of their feed came directly from the fields. He noted that the amount of labor and planning involved was significant.

“It’s like doing a Rubik’s cube,” he said.

One of his biggest challenges is a new rule that requires removal of all livestock 120 days before any produce is harvested and sold for human consumption. (It’s slightly less — 90 days — for crops like tomatoes that aren’t in close contact with the soil.) The withdrawal period is a food safety measure, but it makes setting up a one-year grazing plan extremely difficult, especially with short season vegetables in the mix.

“It’s easier to have a waiting period with a two-year system, and there’s more incentive for cover cropping and grazing within that system,” he said.

Farms growing both produce and livestock are rare, according to Jennifer Tucker, CSU’s small acreage extension coordinator based in Brighton. Livestock producers typically use any available water they have to grow feed or forage for their animals, she said.Boulder County CSU agent Adrian Card said he’d like to see more produce farmers expand their crop rotations to include increasingly valuable forages. He said the price of grass square bales, popular with the area’s horse farms, had doubled in recent years. In addition to diversifying markets, more hay production would help break the weed cycle, he said.

Area farmers said they were interested in exploring new production concepts but were also aware of the drawbacks. Tim Ferrell, owner of Brighton’s Berry Patch Farms, wanted to learn more about living mulches but said he’s had problems in the past with weeds out-competing his cover crops. He also said lack of rainfall was a barrier.

“In a drought year, I like the plastic mulch,” he said. “It has helped immensely with our beds staying moist, and that’s a very good thing.”Likewise, Jerry Monroe, owner of Monroe Organic Farms of Kersey, said planting cover crops between rows of produce was impractical since he didn’t have room to drive a tractor between them. “It’s also hard to do because of the moisture. We don’t get rain, and we just don’t have time to hand-water this stuff,” he said.

Atthowe said after 25 years of study she still had much left to learn about the mysterious interrelationships between plants, soil nutrients and cultivation practices.

“As I like to say, there’s no magic bullets, there’s just magic buckshot,” she joked.